1. Field of Invention
This invention relates in general to fluid fittings, in particular to fluid fittings which are used for attaching conduits to flexible barriers.
2. Description of Prior Art
Many outdoor swap meet vendors make temporary shelters that consist of a cube like framing with thin plastic sheeting or canvas laid horizontally across the top of the frame. The plastic sheeting or canvas acts as a barrier to protect the interior of the shelter from environmental elements. The shelters are usually at least 8 feet wide and 8 feet deep, making the area of the barrier cover at least 64 square feet. 1 mil or 3 mil thick plastic sheeting, or canvas is frequently used as a barrier for these shelters. The plastic sheeting or canvas barrier tends to sag between the frame supports. This sagging creates a depression, so that when it rains, the rain collects on the top of the barrier. The weight of the collected rain may damage and tear the barrier or cause the barrier to collapse. If the barrier is not damaged by the weight of the collected rain, the vendor must somehow drain the collected rain off the barrier before taking the shelter down at the end of the day. This creates some difficulty for these swap meet vendors during rainy weather.
Some swap meet vendors place a pole in the center of the shelter, that raises the center of the barrier, to prevent a depression from forming in the center. This allows rain to drain off the barrier to the sides of the shelter. Unless the barrier is kept taunt there will still be some sagging between the center pole and the sides of the shelter, which will allow rain to collect on top of the barrier. Having rain run off of the sides of the shelter could cause some other problems for the vendors, such as unwanted splashing into the shelter.
A typical bulkhead fitting installed into a hole made in the center of the barrier would create a passage for the collected rain to pass through the barrier. A conduit attached to the bulkhead fitting could direct the rain from the fitting to a container or a drainage area. To adequately drain a surface area of 64 square feet or more the opening in the fitting and the inside diameter of the conduit would need to be at least 0.5 inches in diameter. The conduit would need to be several feet in length to adequately remove the rain away from the shelter. The combined weight of a fitting of adequate size, and a 12 foot conduit with a 0.5 inch inside diameter, plus the weight of the water that flows through the conduit would be at least 2.5 lbs if the fitting and conduit were made of lightweight materials such as plastic. With the fitting attached to the barrier, the barrier would need to support the combined weight of the fitting, conduit, and water flowing through the conduit. Typical bulkhead fittings are designed to be attached to relatively strong and rigid materials such as metal or plastic plates, and are made with narrow flanges for clamping onto the barrier. The flanges usually extend outward perpendicular to the axis of the fitting. Because the flanges are narrow, the combined weight of a typical bulkhead fitting, attached conduit, and water flowing through the conduit would not be readily supported by a thin plastic sheeting or canvas barrier, without the likelihood of tearing or damaging the barrier.
Several types of fittings exist for attaching a conduit to flexible barriers. For example U.S. Pat. Nos. 2,137,223 to Baxter (1938), 2,500,531 to Eger (1950), and 2,747,896 to Quillinan (1956). These prior art fittings have narrow flanges for clamping onto the barrier, and thus will only work effectively with barriers of sufficient thickness to support the fitting. These fittings would not be adequately supported by thin plastic sheeting, canvas, or membrane like material. These fittings rely on the barrier itself to act as a seal, which would only be effective if the barrier is of sufficient thickness and compressibility to act like a seal. These prior art fittings would not seal effectively if installed on a barrier made of thin flexible material such as thin plastic sheeting or canvas.
Typical bulkhead fittings cannot be tightened during installation from one side of the barrier that the fitting is being installed on. The male threaded member of the fitting, that abuts itself on the one side of the barrier, must be prevented from rotating while the female threaded member of the fitting, that abuts itself on the other side of the barrier, is threaded onto the male threaded member. Installing a typical bulkhead fitting onto a large sheet barrier would require two persons, one person to grasp the male threaded member of the fitting to prevent rotation while the other person threads the female threaded member onto the male threaded member.
There are a special class of fittings for attaching a conduit to a barrier that can be installed from one side of the barrier. For example, in U.S. Pat. Nos. 1,637,365 to Wernle (1927), 3,650,551 to Akers (1972), and 4,623,171 to Wilson (1986). Two of these fittings are designed with narrow flanges so that the flanges are able to pass through the opening in the barrier. A narrow flange abutting on the top side of a thin plastic sheeting or canvas barrier, would not distribute the weight of the fitting over an area of the barrier adequate to support the fitting, and the barrier would likely be damaged by the weight of the fitting. One of the fittings is designed with thin metal strips that pass through the opening in the barrier and then expand and abut against the barrier to support the fitting. These thin metal strips would not adequately distribute the weight of the fitting if used with a thin plastic sheeting or canvas barrier, and the weight of the fitting would likely cause damage to the barrier.
Typical roof and floor drains are designed to be installed in structures made of wood, concrete, or steel. For example U.S. Pat. Nos. 3,986,733 to Esser (1976) and 4,730,854 to Cuschera (1988). These drains are too heavy to be supported by an opening in a thin plastic sheeting or canvas barrier.
There is a canvas cover system that has a water catch feature manufactured into the cover, near the edge of the cover. U.S. Pat. No. 3,327,724 to Nielsen (1967). This water catch feature allows rain to drain off of the cover. This water catch feature would be difficult to install on a thin plastic sheeting or canvas barrier already in use as a cover. This water catch feature would work only on a barrier that slants toward the edge of the shelter, and would not work where a barrier slopes toward the center of the shelter, because the catch would let the rain drain into the interior of the shelter. It would be difficult to attach a conduit to this water catch feature, to direct the runoff to a container or drainage area.
There is a canvas umbrella with rain troughs manufactured on the edges. U.S. Pat. No. 3,042,056 to Todorovic (1962). This trough feature would be difficult to install on a thin plastic sheet or canvas barrier already in use as a cover. The trough system would only work where a barrier slants toward the edges of the shelter, and would not work where a barrier slopes toward the center of the shelter.
There is a heavy duty, fiber reinforced tarp, manufactured with a fluid fitting in the center. The fitting is designed so that a garden hose can be attached to the fitting, so that fluids can drain off the topside of the tarp into the fitting and then be directed into the hose. This tarp is sold by a company called Industrial Options, located in Huntington, N.Y. The fitting itself is comprised of a male threaded spout, and a female threaded locknut. The male threaded spout has a flange extending outward from the top end of the spout at an angle perpendicular to the spout. The female threaded locknut has a flange extending outward from one end of the locknut at an angle perpendicular to the side of the locknut. The fitting is assembled onto an opening in the tarp with the tarp clamped between the flange of the male threaded spout and the flange of the female threaded locknut. There is a cement between the two flanges that bonds the fitting to the tarp and prevents the fitting from being removed from the tarp. The cement also acts as a seal between the fitting and the tarp. No evidence of an existing patent for this tarp or fitting has been found.
One problem with this invention is the use of cement to seal the fitting to the tarp. Once the cement dries, the fitting cannot be easily removed from the tarp without damaging the tarp and fitting, thereby not allowing the fitting to be reused again on a different tarp.
Another problem with this invention is that the flange of the male threaded spout has a surface area, which rests against the barrier, that is less than 8 times larger than the area of the cross section of the male threaded spout. If this fitting was used with a thin, non-reinforced barrier, such as 1 mil thick polysheeting, this flange would not distribute the combined weight of the fitting, conduit, and water flowing through the conduit, over a large enough area of the barrier to allow the barrier to support the combined weight of the fitting, conduit, and water flowing through the conduit, and the barrier would likely be damaged.
Another problem with this invention is that the flange of the male threaded spout extends outwardly at an angle that is perpendicular to the male threaded spout. When a tarp is suspended from it's edges, the tarp slopes downward towards its center. This flange does not conform to the sloped surface of the tarp. If this fitting was used with a thin, non-reinforced barrier, such as 1 mil thick polysheeting, the flange would not evenly distribute the combined weight of the fitting, conduit, and the water flowing through the conduit, over the sloped surface of the tarp that is in contact with the flange, and would cause excessive stress on the barrier and would likely damage the barrier.